Medium transport device and image forming apparatus

Abstract

A medium transport device includes a positional corrector configured to transport a medium and correct a position of the medium in a width direction of the medium by moving the medium in the width direction, and an inclination corrector configured to transport the medium and correct an inclination of the medium relative to a transport direction of the medium on an upstream side of the positional corrector in the transport direction, the inclination corrector being disposed at a position where the medium is transported in a flat posture.

What is claimed is: 
     
       1. A medium transport device comprising:
 positional correction rollers configured to transport a medium and correct a position of the medium in a width direction of the medium by moving the medium in the width direction; and 
 inclination correction rollers configured to transport the medium and correct an inclination of the medium relative to a transport direction of the medium on an upstream side of the positional correction rollers in the transport direction, the inclination correction rollers being disposed at a position where the medium is transported in a flat posture, wherein 
 the positional correction rollers comprise:
 first positional correction rollers configured to nip and transport the medium; and 
 second positional correction rollers disposed on an upstream side of the first positional correction rollers across an arcuate transport path for the medium and configured to nip and transport the medium, and 
 
 the positional correction rollers are configured to correct the position of the medium in the width direction by moving the first positional correction rollers and the second positional correction rollers in the width direction with the medium nipped by the first positional correction rollers and the second positional correction rollers. 
 
     
     
       2. The medium transport device according to  claim 1 , further comprising:
 a medium transport member disposed along the arcuate transport path and configured to nip and transport the medium, 
 wherein, during correction of the position of the medium in the width direction by the positional correction rollers, a portion of the medium transport member disposed on an outer side of an arc of the arcuate transport path is separated from the medium. 
 
     
     
       3. The medium transport device according to  claim 1 , wherein the inclination correction rollers adjoin the positional correction rollers on the upstream side in the transport direction. 
     
     
       4. The medium transport device according to  claim 2 , wherein the inclination correction rollers adjoin the positional correction rollers on the upstream side in the transport direction. 
     
     
       5. The medium transport device according to  claim 3 , further comprising:
 medium transport members disposed on an upstream side of the inclination rollers in the transport direction and configured to nip and transport the medium, 
 wherein, during correction of the inclination of the medium by the inclination correction rollers, the medium transport members are separated from the medium. 
 
     
     
       6. The medium transport device according to  claim 4 , further comprising:
 medium transport members disposed on an upstream side of the inclination rollers in the transport direction and configured to nip and transport the medium, 
 wherein, during correction of the inclination of the medium by the inclination correction rollers, the medium transport members are separated from the medium. 
 
     
     
       7. The medium transport device according to  claim 5 , wherein the medium transport members to be separated from the medium during the correction of the inclination of the medium by the inclination correction rollers are selected based on a length of the medium in the transport direction. 
     
     
       8. The medium transport device according to  claim 6 , wherein the medium transport members separated from the medium during the correction of the inclination of the medium by the inclination correction rollers are selected based on a length of the medium in the transport direction. 
     
     
       9. An image forming apparatus comprising:
 the medium transport device according to  claim 1  configured to transport a medium; and 
 an image former configured to form an image on the medium. 
 
     
     
       10. A medium transport device comprising:
 positional correction means for transporting a medium and correcting a position of the medium in a width direction of the medium by moving the medium in the width direction; and 
 inclination correction means for transporting the medium and correcting an inclination of the medium relative to a transport direction of the medium on an upstream side of the positional correction means in the transport direction, the inclination correction means being disposed at a position where the medium is transported in a flat posture, wherein 
 the positional correction means comprises:
 a first positional correction means configured to nip and transport the medium; and 
 a second positional correction means disposed on an upstream side of the first positional correction means across an arcuate transport path for the medium and configured to nip and transport the medium, and 
 
 the positional correction means is configured to correct the position of the medium in the width direction by moving the first positional correction means and the second positional correction means in the width direction with the medium nipped by the first positional correction means and the second positional correction means.